Talk to General Physician on Query About Multivitamins

Assalam o Alaikum, I am asking this for my almost 14 year old sister, if she can consume multivitamin gummies from nature's bounty. She sleeps less, has difficulty concentrating, feels lethargic. Cousin's her age are taking it, and I wanted to know if it's safe for her too. If not nature's bounty please suggest any other vitamins for the above mentioned symptoms and for hair, nail and skin too. She has hit puberty and her cycle is normal too Alhumdulilah. No other health issues are concerned. She is tall and skinny and I think she doesn't get enough nutrients as kids these days avoid necessary greens and fruits. Ramadan is coming too and I want her to not feel lethargic or weak. JazakAllah.